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Are You Sure You Understand USP <621>?In this column, we look at the current version and the update of USP <621> on high-performance liquid chromatography (HPLC) that becomes effective 1st May 2025.
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Rapid LC Determination of UV Filters in Cosmetics using Ethanol as the Mobile PhaseA rapid and environmentally friendly LC method for the simultaneous determination of 12 UV filters in cosmetic samples using ethanol as the mobile phase.
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Quantitative Proteomic Workflow for Discovery of Early Rejection Kidney Transplant Peptide Biomarkers and Subsequent Development of SRM Assays in UrineThe accurate diagnosis of renal allograft rejection currently depends upon a biopsy. Transplant medicine would benefit greatly from the availability of noninvasive tests for early detection of rejection and immunosuppressive drug therapeutic monitoring. Only a limited number of studies have been published to date on specific proteins associated with allograft rejection. Typically, renal dysfunction due to humoral transplant rejection or other pathologies results in the increase of protein excreted in urine (1–5). In blood, endogenous peptides (not generated by trypsin digestion ex vivo) are likely candidate biomarkers for many diseases and pathologies as they are secreted from tissues and enter the bloodstream (6,7). The analysis of endogenous protein and peptide fragments in urine can provide a noninvasive, early indication of kidney transplant rejection or disease.
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Real-Time Profiling of Volatile Malt Aldehydes Using Selected Ion Flow Tube Mass SpectrometryThe authors use headspace SIFT-MS to target and identify volatiles in various malt aldehydes. The specificity and speed are compared to current methodology.
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Analysis of Polymers and Protein Nanoparticles using Asymmetrical Flow Field-Flow Fractionation (AF4)This article describes some of the latest developments for the analysis of polymers and nanoparticles.
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GCxGC-FID for Qualitative and Quantitative Analysis of PerfumesExploring the use of GCxGC-FID as a technique for qualitative and quantitative analysis of perfumes
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Monitoring Emissions From Respiratory Medical Devices in Accordance With ISO 18562-3This study describes the monitoring of potentially harmful volatile organic compounds (VOCs) emitted from respiratory medical devices, by pumped sampling and thermal desorption–gas chromatography–mass spectrometry (TD–GC–MS) analysis in accordance with ISO 18562 part 3. Emissions from two sets of face-mask supply tubing and three nasal cannulas were compared, and all were found to emit VOCs at levels that may give cause for concern.
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Harnessing the Benefits of HPLC with Fluorescence Detection for the Analysis of Aflatoxins in Raw MilkThis article highlights the analytical advantages of analyzing raw milk for aflatoxins, focusing on M1, using high performance liquid chromatography (HPLC) with fluorescence detection - without derivatization. Leveraging M1’s native fluorescence, this is particularly welcome since this approach affords the requisite analytical sensitivity with minimal method complexity.
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Rapid Screening of Pesticides Using U-HPLC/MSThe screening of pesticides, mycotoxins, and veterinary drugs is of great importance in regulated environments such as food or feed analysis. Due to some of the limitations of traditional triple quadrupole approaches (for example, targeted analyte detection, limited number of compounds, and unidentified unknown compounds), there is currently a trend towards use of full-scan MS data for the analysis of residue samples. Current screening approaches mainly rely on the use of ToF instruments coupled to U-HPLC delivering mass accuracy (~5 ppm) at a maximum resolution of <15,000. This can produce inaccurate mass measurements due the presence of unresolved background matrix interferences. In this work we show a full-scan MS screening approach with the Thermo Scientific Exactive mass spectrometer, a novel single-stage Orbitrapâ„¢ MS capable of providing precise mass accuracies at resolutions of up to 100,000 without the need for internal mass calibration.
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Automated Solid Phase Extraction for Efficient Extraction of Fluoroquinolone Antibiotics from FishThe global demand for fish as a natural source of fresh animal protein, essential fats, minerals, and vitamins continues to rise with the human population.
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Simultaneous Determination of Formononentin, Biochanin A, Daidzen and Genistein in Trifolium pratense (Red Clover) by HPLCA simple and rapid HPLC method was established to simultaneously determine the active ingredients of red clover.
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Evaluation of Extraction Methods and Bias Correction by EPA Method 6800 Protocol for Mercury Species in Tuna Fish Tissue Using an Ion Chromatograph Coupled to an ICP–MSMercury pollution mainly originates from industrial activities such as chlorine production, garbage incineration and above all coal-fueled power generation. The US Environmental Protection Agency (US EPA) considers mercury as highly toxic with a pronounced accumulative and persistent character.
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Method Selection for Trace Analysis of Genotoxic Impurities in PharmaceuticalsThis article describes methods to quantitatively analyse genotoxic and potentially genotoxic impurities in pharmaceutical ingredients
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Simultaneous Headspace-GC–FID Analysis for Methanol and Ethanol in Blood, Saliva and Urine: Validation of Method and Comparison of SpecimensA simultaneous headspace-GC–FID method was validated to establish methanol and ethanol assessment in blood, urine and saliva.
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High Resolution UHPLC Analysis of Naringin in Grapefruit JuiceGrapefruit juice was analysed by gradient UHPLC for naringin - a major flavanoid in grapefruit juice that gives it its bitter taste. A ZORBAX Rapid resolution HD (RRHD) StableBond-C18 2.1 ? 150 mm, 1.8 ?m column was able to resolve over 60 peaks, including naringin in 7 minutes, and was re-equilibrated in just three minutes by operating at a high flow rate (0.8 mL/min). The high pressure generated (965 bar) is well within the 1200 bar operating range of the RRHD column and 1290 Infinity LC.
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Screening by LC–MS-MS and Fast Chromatography: An Alternative Approach to Traditional Immunoassays?A new technique was developed based on liquid chromatography coupled with tandem mass spectrometry to analyze drugs that are not part of current immunoassay screening, specifically zolpidem, zopiclone, and zaleplone, or "z-drugs."
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Method Development for Drug Impurity Profiling (Part 2)A systematic approach to developing drug impurity profiling methods.
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Method Development for Drug Impurity Profiling (Part 2)A systematic approach to developing drug impurity profiling methods.
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UHPLC Coupled with Fourier Transform Orbitrap for Residue AnalysisThe trend in residue analysis has changed from target-oriented procedures towards accurate mass full-scan MS techniques. This article describes these developments and addresses the implications of 2002/657/EC.
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Dual Flow ChromatographyDual flow chromatography (DFC) separations are performed with back and forth flow for rapid method development, design of experiments (DOE), quality-by-design (QbD), or high-throughput chromatographic purification. Although different than conventional unidirectional flow through chromatography, chromatographic principles still control the separations. Selectivity coefficients and Langmuir adsorption isotherms control the separation chemistry properties of the column and dictate the mobile phase conditions needed to achieve separation. However, the kinetic rates of diffusion and interaction of mobile phase molecules with the stationary phase, column channeling, and other column properties are not germane to the practice of DFC. Chromatographic conditions developed with DFC can be scaled to any size, including laboratory and industrial preparative columns.
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Innovations and Strategies of Sample Preparation Techniques to Reduce Matrix Effects During LC–MS/MS BioanalysisReducing matrix effects during LC–MS/MS bioanalysis is paramount. Improving sample preparation techniques is the best way to combat this issue.
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Diamonds are a Chromatographer's Best Friend?Pavel Nesterenko from ACROSS about his work on the potential of diamond-related substances as stationary phases
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Hydrogen Deuterium Exchange Mass Spectrometry: An Emerging Biophysical Tool for Probing Protein Behaviour and Higher-Order StructureThis article looks at how hydrogen-deuterium exchange mass spectrometry (HDX-MS), an MS-based labelling approach, has begun to serve as a means for performing routine biophysical analysis.
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BTEX Determination in Gasoline Containing Ethanol by Single Oven MDGCThe determination of BTEX in gasoline is usually performed in accordance with the standard test method ASTM D3606 using gas chromatography. However, particularly in the presence of ethanol, co-elutions are observed in one-dimensional chromatography. In this application note a method is described applying multidimensional GC to overcome the separation problem.
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Novel Analytical Methods for the Discovery and Trace Analysis of Biochemically Active CompoundsNovel analytical methods for the discovery and trace analysis of biochemically active compunds in three main area are described: protein analysis, screening technologies and multidimensional separations.
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A Simple Instrumental Approach for "Supercritical" Fluid Chromatography in Drug Discovery and Its Consequences on Coupling with Mass Spectrometric and Light Scattering DetectionA simple experimental setup applied in a drug discovery laboratory illustrates some anomalies and misconceptions about supercritical fluid chromatography for drug discovery.
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Liquid Chromatography–Time-of-Flight Mass Spectrometry for Cannabinoid Profiling and Quantitation in Hemp Oil ExtractsA primary impediment to cannabinoid research is the fact that materials possessing psychoactive Δ-9-tetrathydrocannabinol are considered Schedule I drugs as defined in the U.S. Controlled Substances Act. An alternative source of cannabinoids may be found in hemp oil extracts. Hemp contains a low percentage of Δ-9-tetrathydrocannabinol (THC) by weight but relatively high amounts of non-psychoactive cannabinoids. The liquid chromatography-time of flight mass spectrometry (LC-TOF) method presented herein allows for the accurate, precise and robust speciation, profiling and quantification of cannabinoids in hemp oil extracts and commercial cannabinoid products for research and development laboratories. The method was determined to chromatographically separate 11 cannabinoids including differentiation of Δ-8-tetrahdrocannabinol and THC with excellent linear dynamic range, specificity and sensitivity.
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Electrochemistry and LC–MS for Metabolite Generation and Identification: Tools, Technologies and TrendsThis article provides an introduction to electrochemical liquid chromatography mass spectrometry. The instrumental set-up is presented and selected applications in drug development processes are discussed.
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Novel Analytical Methods for the Discovery and Trace Analysis of Biochemically Active CompoundsNovel analytical methods for the discovery and trace analysis of biochemically active compunds in three main area are described: protein analysis, screening technologies and multidimensional separations.
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Application of Microbore UHPLC–MS-MS to the Quantitation of In Vivo Pharmacokinetic Study SamplesLiquid chromatography coupled with tandem mass spectrometry (LC–MS-MS) is the primary bioanalytical technique used today within the pharmaceutical industry for the quantitation of small molecules in biological matrices such as plasma. In recent years, chromatographic resolution has been improved with the development of ultrahigh-pressure liquid chromatography (UHPLC) systems that utilize smaller diameter particles (< 3 μm) and operate at pressures > 5000 psi. While most LC systems utilized for this application are optimized for columns with internal diameters (i.d.) between 2.0 and 4.6 mm, a new UHPLC system designed for microbore columns (≤ 1 mm i.d.) has been introduced recently. This article will discuss the advantages of using a microbore UHPLC system coupled with a tandem mass spectrometer for the quantitation of in vivo pharmacokinetic samples. These advantages include reduced sample and solvent consumption, improved chromatographic resolution and speed, and reduced mass spectrometer source..
